DE2823297A1 - THERMOPLASTIC HOT MELT ADHESIVE - Google Patents

Description

Applicant: Unitech Chemical Ine »-, 115 West Jackson Boulevard, Chicago, Illinois, USA

Thermoplastic hot-melt adhesive

The invention relates to hot melt thermoplastic adhesive blends of copolymers and epoxy resins and methods for theirs Manufacturing.

Hot melt adhesives are applied to substrates such as metals, glass, wood and the like in the heated, molten state. After cooling, the hot melt adhesive forms a bond between the substrates. Thermoplastic adhesives nind hot melt adhesives that form a bond that is in the Essentially heat reversible manner is that the adhesive is at elevated temperatures with a resultant loss of bond strength again softens and flows.

Superior thermoplastic hot melt adhesives have high peel strength and high tensile shear strength. This results in an adhesive bond that is both tough and elastic. Adhesives that have good tensile shear strength but poor peel strength are tough _? however brittle. Adhesives that have good peel strength but poor tensile shear strength are elastic, but relatively weak. Another very beneficial property of hot melt adhesives is acceptable creep resistance at elevated temperatures. A disadvantage of many hot melt adhesives is that they have a relatively short pot life, that is, they often cannot be held at their application temperatures for extended periods of time without losing their ability to be applied to substrates

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goes or without losing their adhesive strength. A short pot life is usually indicated by significant increases or decreases in viscosity when the adhesive in the pot is held at its use temperature.

From publications such as Cella "Journal of Polymer Science", Symposium no. 42, pages 727-740 (1973) and the US-P8 ^l s 3,723,568 and 3,784,520, it is already known that certain hydroxy-terminated poly ( ester / ether) -blockcopolymar have thermoplastic properties. These polymers, which are used as starting materials in the subject of the parallel US application SN 590 622, show high tensile shear strengths but very low peel strengths when they are used alone as thermoplastic hot melt adhesives. Epoxy resins are widely used as curing agents for adhesives, and they have found wide use in crosslinking or otherwise reacting with various substances in the formation of thermoset adhesives. When epoxy resins are used alone, they are very brittle solids at room temperature and have virtually no tensile shear or peel strength.

The object of the invention is therefore to provide thermoplastic hot melt adhesives To provide mixtures that have high tensile shear strengths, exceptionally high peel strengths and have creep resistance at elevated temperatures and have a long pot life.

The invention is also intended to provide a method for forming mixtures, which are improved thermoplastic hot melt adhesives that are both tough and elastic are available be asked.

The invention also aims to provide thermoplastic hot melt adhesives be made available, the superior

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Adhesive properties, especially high peel strength even when used on untreated substrates will.

Furthermore, according to the invention, thermoplastic hot melt adhesives are intended are made available the one-sensible Have viscosity at application temperatures and which have the ability to operate at these elevated application temperatures To be held for long periods of time while having a stable viscosity and retention of adhesive strength.

The subject matter of the invention is a thermoplastic hot melt adhesive, which is characterized in that it is a mixture of an epoxy resin and a hydroxy-terminated poly (eater / ether block copolymers of formula I:

OR "0

CO (R ^f C%

COR ¹¹ OH

where R ¹ and R "represent alkyl groups, alicyclic groups, acyclic groups, aryl groups or arylalkyl groups having 2 to 12 carbon atoms, P is a number from 2.4 to 136.0, a is a number such that the proportion of" hard "segment in the first set of brackets is about 70 to 20% by weight of the copolymer, and b is a number such that the proportion of the" soft "segment" in the second set of brackets is about 30 to 80% by weight. % of the copolymer.

The mixtures are formed by heating and mixing an epoxy resin and a copolymer (I) until a Compatible thermoplastic mixture is formed. When

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When needed, the hot mixture can be applied to substrates and cooled; η can be left, creating a thermoplastic Bonding of the substrates is formed »The substrates can be used if necessary preheated or post-heated to ensure the bond strength to improve·

Dj. e mixtures according to the invention are based on the discovery that mixtures of the copolymer (I) with epoxy resins improve the adhesive properties of the copolymer. These compounds enter into no noteworthy chemical reaction with one another, but the epoxy resin works together with the copolymer to improve its thermoplastic high-speed wear properties. Dor mechanism of this phenomenon, however, is not yet known, "Presumably, the long pot life and viscosity stability of the compatible mixtures in their application TEMPERE doors at least /.um Toil by the recognized observation explains WTcltm that generally hydroxy groups with epoxy resins in the absence of an acid catalyst his ¹ wenif-j react.

The copolymers (I) of the mixtures according to the invention are essentially linear, hydroxy-terminated poly (ester / ether) block copolymers with a low to moderate molecular weight (about AOOO to 25,000). The molecular weights of these polymers mentioned herein are average molecular weights determined by conventional and group analysis for Hydrox3 ^r G, r upper, based on titration with succinic anhydride.

The hydroxy-terminated, essentially linear poly (ester / ether) -blocl: copolymers (I) is a polymeric reaction product from (1) one or more aromatic, aliphatic or cycloaliphatic !! Dicarboxylic acids or ester-forming derivatives thereof, (2) one or more low molecular weight aliphatic, alicyclic, acyclic or aromatic diol and (3) one

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or more difunctional polyethers including poly (alkyl ether) glycols.

Suitable aromatic dicarboxylic acids are 2.B. Terephthalic acid, Phthalic acid, isophthalic acid, bibenzoic acid, bis-Cp-carborsypho- · nyl) -metiic acid, p-oxy- (p ~ carboxyphenyl) -benzoic acid, Ätivflenbis- (p-oxybenzoic acid ), 1, fj'-naphthalenedicarboxylic acid, 2,6-nephthalenedicarboxylic acid, 2,7-IiaphtlialincU carboxylic acid, phenanthrenes dicarboxylic acid and 4,4'-Sul: fonyldibenzoic acid. Suitable e & ter ~ Forming derivatives are, for example, methyl, ethyl, phenyl and monomeric ethylene glycoltister and acid halides, such as acid chlorides of such aromatic dicarboxylic acids.

Representative aliphatic and cycloaliphatic diacid acids are, for example, sebacic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, succinic acid, malonic acid, oxalic acid, azelaic acid, suberic acid, pimelic acid, maleic acid, fumaric acid, 4-glutaric acid _i 2-dicarboxylic acid, 2-ethylcarboxylic acid, 2.2 ^t _i 3 _i 3 ^I ~ TetraroethylberiiGteinsäi3re _> Oyclo- ι pentanedicarboxylic acid, 4,4 * -Blcyclohexyldicarborisätire, 3,4-furan ^ dicarboxylic acid and 1,1-cyclobutanedicarboxylic acid ^ V / additional examples _; Ie are ester derivatives as mentioned above with regard to the aromatic dicarboxylic acids.

Suitable diols with low molecular weight are e.g. dihydroxy compounds, such as ethylene glycol, eropylene glycol, tetramethylene glycol, Pentamethylene glycol, 2,2-dimethyltrimethylene glycol, Hexamethylene glycol, decamethylene glycol, 1,2-propanediol, 3-methyl-1,5-pentanediol, 1,3-cyclobutanediol, 1,4-cyclohexane-B, B-diethanol, 1,4-Cyclohexanedimethanol, 1,3-Cyclopentanedlmethanol, 1,4-cyclohexanediol, resorcinol, hydroquinone, 1,5-dihydroxynaphthalene, Bis (p-hydroxy) diphenyl, bis (p-hydroxyphenyl) methane and bis (p-hydroxyphenyl) propane.

The difunctional polyethers are given by the general formula:

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R.
H-C "-0 (CH ₂ ) _x jj

indicated, wherein R II and CH * includes, χ is an integer of Is 1 to 11 and η is a number of 2.4 bits; 136.0 is. Representative At fipxole for such compounds are the following FoIy- (s.lkylßnäthc: r) -glycols: Poly (ethylene ether) glycol, poly (propylene ether) glycol, Poly (tetramethylene ether) glycol, poly (pentamethylene ether) glycol, Poly (hexoinethylene ether) glycol, Poly (heptamethylene ether) -glycol, poly (oetamethylene ether) -gllycol, Poly (nonamethylene ether) glycol and poly (de came ethylene ether) glycol, such polymers having an average molecular weight in the range of about 400 to 6000.

Darhydroxy-terminated poly (ether / ether) block copolyinero (I) contains two types of blocks, namely a "soft" segment, which gives the polymer a relatively low glass transition characteristic, and an elastomeric character , and a "hard" Ssgmsntj which gives the Polyuex'en a crintalline earoich with a relatively high melting point in order to reduce slipping of the chain in the absence of elevated temperatures. For example, the preferred hydroxy-terminated copolymer (I) is made from dimethyl terephthalate, dimethyl isophthalate , 1,4- butanediol (tar · methylene glycol) and poly (tetratiethylene ether) glycol are produced. Both R 'and R "are (CH ₂ ) ^. Da3" hard "segment has an average molecular weight of about 220 and the following structure:

0 0

-c- / o) -co (CH ₂ ) ₄ c

The "soft" segment has an average molecular weight of about 1130 and the following structure:

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oo

- / O VCO - [(CH ₂ J ₄ O] p «

where ρ is an integer of about 8 Ms about 23.

The proportion of the "soft" segment is about 30 Ms 80 G '/ tf .- ^ ij of the total polymer, preferably ctv: a 40 bin 70 wt .- / S * I) ^ r The proportion of the "hard" segment is around 70 to 20 Ge \ v .-- ?: < of the total polymer, preferably about 60 to 30 Gow .--? <>.

Epoxy resins suitable for making the compound mixtures include those based on bisphenol A and epichlorohydrin, the epoxy equivalents in the range of about 175 to 4000 and average molecular weights from about 350 to 3S00 have and which by ίοIgtηώ; general formula are shown:

/ - \ _t 3 / - \ —r — Ox ο> -C ~ (ο VOC

OH

^Y n

-0 ~ / ο Χ

i / -Λ CII

Also included are phenolic novolak epoxy resins with follow the formula:

ο - CII

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The epoxy resin can also be the tetraglycidyl ether of 1,1,2,2-tetra-bis (hydroxyphenyl) ethane or a cycloaliphatic epoxide such as 3,4-epoxy-6-methylcyclohexylmethyl-3,4-epoxy-6-methylGyclGhexanecarboxylate, be.

These epoxy resins must melt at the application temperature of the respective copolymer (I), which is also melted at this temperature. This temperature will vary depending on the high temperature creep resistance desired. Typical application temperatures for the inventive blends are in the range of about 130 to about 205 ⁰ C. The epoxy resins must also be capable, with the copolymers (I) compatible mixtures to bildeiij so that a homogeneous mixture is obtained. The epoxy resin is preferably present in the mixture in amounts of about 5 to about 50% by weight, while the proportion of the copolymer (I) is about 50 to 95% by weight of the total mixture.

The mixtures are thermoplastic adhesives that melt at preselected temperatures and are suitable for bonding substrates such as metals, glass, wood and the like. They have a very high tensile shear strength of about 63.2 to about 126.5 kg / cm. The measurements of the tensile shear strength are carried out in such a way that an overlapping bond with 2.54 × 2.54 cm on a cold-rolled steel without a base layer at 25 ^° C. was tested. The mixtures show an exceptionally high peel strength of about 893 to about 2679 kg / m 2. The measurements of the peel strength effected in such a manner that (thickness about 635 Jim) to aluminum without basic layer was tested at 25 ⁰ C. The mixtures consist the Kriechbeständigkeitstest at 149 ° C when the copolymer (i) has a melting point of not less than about 160 ⁰ C. The creep resistance measurements are made by forming an overlap bond of 2.54 χ 2.54 cm on cold rolled steel, suspending a load of 2000 g, and placing the bonded steel in an oven at about 149 ^° C became. Of

: r; jB09850 / Q769

- or - A3

Mixture passes the creep resistance test if the bond lasts longer than 10Oh.

These mixtures also have a suitable initial viscosity after they have been brought to their respective application temperatures. Within a range of typical application ^{temperatures of approximately 130 to 205 °} C., the initial viscosity of the mixture just formed is approximately 100 to 800 poise. Another feature of these mixtures is that the initial viscosities remain relatively stable when the mixtures are held at application temperatures for several hours. It is a feature of the products according to the invention that their pot life is particularly long. The viscosity of the initial application temperature therefore neither increases nor decreases appreciably when the mixture is held at this temperature for periods of 8 hours or more .

An appreciable increase in viscosity is undesirable because such an increase greatly reduces the workability of the hot melt adhesive at the application temperature. The extent of viscosity increase in the inventive mixtures which are held at hot melt application temperatures in the hot melt pot is ¹ probably never controlled in the first Li by the very hesitant reaction between the epoxy resins and the hydroxyl-terminated copolymer (I). Furthermore, a significant reduction in viscosity for a hot melt adhesive with a long pot life is undesirable because such a reduction is generally associated with a reduction in adhesive strength . The adhesive strength and toughness of the thermoplastic bonds formed by the mixtures according to the invention will be maintained, regardless of whether the mixture was applied very shortly after reaching the application temperature or whether the mixture was used in the hot melt pot after 8 hours or more.

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ORIGINAL INSPECTED

In the method of the present invention, the copolymer (I) and the epoxy resin are heated until each component is melted. It is then possible to mix the two molten components until a compatible and substantially homogeneous mixture has been formed at about the application temperature. In the heating step v / ground preferably the components heated to about 205 ⁰ C to a temperature of about the 130th The mixed components can be held at the approximate application temperature for up to 8 hours or more. The mixture is then applied to the substrates to be joined at the application temperature. Preheating or postheating of the substrates can be useful, especially in the case of metals, in order to obtain more complete moistening of the bonded surfaces and higher bond strength. The substrates are brought together and the assembly (ie, the substrates bonded with the mixture) is allowed to cool to ambient temperature. At this point the thermoplastic bond has formed.

The hydroxy terminated copolymers (1) have a moderate molecular weight of about 4,000 to 25,000 obtained by a polymerization reaction between the dicarboxylic acids or esters, the diols and the difunctional polyethers described herein. Preferably, the initial reaction is carried out under nitrogen gas at a pressure within an approximate range of 1 to 15 mm Hg, preferably 5 to 10 mm Hg, and at a temperature of about 150 to 250 ^° C., preferably 190 to 210 ^° C., usually in the presence an ester interchange catalyst and an antioxidant or stabilizer. During this process, methanol, which is a reaction by-product, distills over. After the methanol distillation is complete, the temperature is increased to about 220 to 280 ^° C., preferably about 240 to 260 ^° C., and the pressure is kept within the range of about 1 to about 15 mm Hg for about 1 to 6 hours, thereby forming a polymer with low to moderate

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"No

according to molecular weight (about 4,000 to 25,000) is formed. The molecular weight increases with the reaction time.

Suitable ester exchange catalysts are, for example, organic titanates, such as tetrabutyl titanate and tetraisopropyl titanate, either alone or in combination with magnesium or calcium acetate, complex titanates, vrie MgHTi (OR) ₆ or NaHTi (OR) ₆ , made from alkali or alkaline earth metal alkoxides and titanate esters, inorganic titanates such as lanthanum titanate, calcium acetate / antimony trioxide mixtures and magnesium alkoxides.

The stabilizers can be phenol derivatives _? such as 4.4 ^! -Bis-2,6 ~ di-tert. ~ Butylphenol), 1,3,5 ~ trimethyl ~ 2,4,6-tris- (3,5 »" di ~ tert-butyl-4 ~ hydroxybensyl) »benzene and 4,4-butylidene-bis- (4-tert-butyl-aa-cresol). Further suitable stabilizers are, for example, inorganic metal salts or hydroxides and organic complexes such as nickel butyl dithiocarbonate, manganese salicylate and copper 3-phenyl salicylate. Suitable as Stabilizers are also mixtures of hindered phenols, including esters of thiopropionic acid, mercaptides and phosphite esters. Preference is given to amine stabilizers, such as, for example, ρ, ρ-dioctyldiphenylamine, N, N-bis- (ß-naphthyl) -p-phenylenediamine, N, N -Bis- (1 -methylheptyl) -p-phenylenediamine, N-phenyl-N ^f - (p-toluenesulfonyl) -p-phenylenediamine, N- (3-hydroxybutylidene) -naphthyleynine, diphenylamine / acetone condensates and N-phenylnaphthylamine / Acetone condensates.

A representative example of the polymerization reaction involving a hydroxy terminated poly (ester / ether) block copolymer (Formula I) forms is the following reaction in which the dicarboxylic acid or ester is a mixture of dimethyl phthalates, the diol is a glycol and the difunctional polyether Polyalkylene ether glycol is:

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COR "0

HO (RO-)

HOR "OH + HO (R ¹ Q) -H

Γ ·

^ CO (R «Ofcr ir P

OR "OH

(D

R ¹ and R "denote alkyl groups, alicyclic groups, acyclic groups, aryl groups or arylalkyl groups with 2 to 12 carbon atoms, ρ is a number from 2.4 to 136.0, a is a number such that the proportion of" hard " segments amounts to 6 of copolymers within the first set of parentheses about 70 to 20 wt .- $, and b is a number such that the proportion of "soft" segments in the second set of parentheses about 30 to 80 Gev, -% of the copolymer amounts to.

The actual values of a and b are functions of the starting materials used and their molecular weights. For example, according to a preferred embodiment, the dicarboxylic acid or the corresponding ester is a combination of about 0.50 bps 0.90 mol of dimethyl terephthalate with about 0.10 to 0.50 mol of dimethyl isophthalate, the diol being 1,4-butanediol and the difunctional polyethers is poly (tetramethylene ether ) glycol with a molecular weight range of about 600 to 2000. In this preferred embodiment, the range for a is about 0.45 (where the proportion of the hard segment is about 20 % by weight ) to about 0.96 (where the proportion of the hard segment is about 70% by weight). The value for b is about 0.55 (where the proportion of the soft segment is about 80% by weight) to about 0.04 (where the proportion of the soft segment is about 30% by weight).

The invention is illustrated in the examples.

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ORIGINAL INSPECTED

example 1

A hydroxy-terminated poly-ester / ethereal block copolymer with a molecular weight of about 20,920 was prepared in the manner that the following starting materials under Sticlistoffatmosphäre in a Ross mixer with 7.5 1 were converted:

1224 g polytetramethylene ether glycol (molecular weight about 1000)
1274 grams of dimethyl terephthalate

546 grams of dimethyl isophthalate
1102 grams of 1,4-butanediol.

In this approach the molar ratio of dimethylterephtba «- lat to dimethyl isophthalate 70:30. This reaction was carried out in the presence of tetrabutyl titanate / magnesium acetate, an ester interchange catalyst, and octylated diphenylamine, an antioxidant, carried out.

At the beginning, the reaction ^{temperature was kept at 200 °} C. until no more methanol distilled over. This was the case after about a h, after the temperature of 200 ⁰ C had been reached. The pressure was then decreased to 6 mm / Hg and the temperature was raised to 250 ⁰ C. These conditions were maintained for 2 hours. The reaction mixture was cooled to 200 ⁰ C and the resulting hydroxy-terminated poly (ester / ether) block copolymers (I) was recovered. This polymer had a molecular weight of about 19670, a melting point of 140 ° C, and it is identified as "P-140" in Table I. It was then heated to its melting point along with various ratios of epoxy resins. Two different resins were mixed in in such amounts that the final mixture contained 10, 15 or 20 % by weight of epoxy resin and 90, 85 or 80% by weight of copolymer (I). A resin designated as A is the reaction product of bisphenol A with epichlorohydrin and it has a

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Epoxy equivalent weight of about 900. The other resin than B is a similar product with an epoxy equivalent weight of about 5000. The test results so for the various thermoplastic products are listed in Table I.

Ex iel 2

The procedure was as in Example 1, with the only exception that the ratio of dimethyl terephthalate to dimethyl isoph thalat has been changed to 80:20. This became a copolymer (I) having a molecular weight of about 21,500 and a melting point of 160 ° C. This is called "P-160" in the Table I denotes.

Example 5

The procedure of Example 1 was repeated with the only exception that the molar ratio of dimethyl terephthalate to dimethyl isophthalate was changed to 90:10. Thereby, a copolymer (I) having a molecular weight of about 18700 and a melting point of 180 ⁰ C was obtained. The product is identified as ^M P-180 ^M in Table I.

Example 4

The procedure of Example 1 was repeated with the only exception that the molar ratio of dimethyl terephthalate to dimethyl isophthalate was changed to 100: 0. As a result, a copolymer (I) having a molecular weight of about 21,600 and a melting point of about 195 ° C., which is designated as ^M P-195 ^rt in Table I, was obtained.

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Copoly-
meres % Epo
xyharz Tabel -if
I. Train-
shear
firm
ability ₂
kg / cm 2823297 Creeping
firm
at
1490C Attempt no.
of the mixture P140 0 use
detes
Epoxy
resin 69.5 Deduction "
hard-
- speed
kg / ra fails P140 P140
P140
P140 10
15th
20th - 66.1
71.0
73.1 286 fails
fails
fails P140-10-A
P14O-15-A
P140-20-A P14O
P140
P140 10
15th
20th A.
A.
A. 74.5
82.3
89.9 1964
2500
2464 fails
■ fails
fails P140-10-B
P14O-15-B
F140-20-B P160 0 B.
B.
B. 75.2 2679
2589
1518 consists P160 P160
P160
P160 10
15th
20th - 87.1
94.2
109.7 286 consists
consists
fails P160-10-B
P160-15-B
P-160-20-B P180 0 B.
B.
B. 75.2 1089
1429
1161 consists P180 P180
P18Ö
PI80 10
15th
20th - 74.5
87.2
96.3 179 consists
consists
consists P180-10-A
P180-15-A
P180-20-A P180
P180
PI80 10
15th
20th A.
A.
A. 92.8
94.9
111.8 482
607 '
679 consists
consists
consists P180-10-B
P180-15-B
P180-20-B P195 0 B.
B.
B. 68.9 911
1321
1107 consists P195 P195
P195 10
20th - 92.1
99.9 36 consists
consists P195-10-A
P195-20-A P195
P195 10
20th A.
A. 106.9
120.2 107
143 consists
consists P195-10-B
P195-20-B B.
. B. 286
196

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The P14O ~ = copolymers alone tind mixtures of P14O with the epoxy resin A _s all presented according to Example 1 were tested on the ViskoaltütsstaMlität over periods _s. the pots correspond to those which are advantageous for adhesives that are usually used. Each sample is kept at 20 ° C and the viscosity of each sample is at different time intervals)? according to; The results obtained are summarized in Table II. It can be seen that the unmixed copolymer P14O experienced a pronounced viscosity in front of it, which leads to a loss of toughness and durability. The ! P140-10-A "and P14O" 2O ~ O mixtures actually showed an increase Oer viscosity until after about 5 hours of Gclauistand was reached. The fact that Pi40-15-A ^j -Gfcmisch showed a remarkable, swerto viscosity stability, yoboi the viscosity remained relatively constant in the course of the 8-hour test period. No loss of toughness was observed in thermoplastic bonds formed later «

P-140 Tabel II 500 P-140-1 765 Viscosity (poise) at 204 ⁰ C 500 465 654 P-140-10-A Ρ-140-20-Λ 540 560 Oh 540 540 590 490 1 h 460 320 690 410 2 h 410 170 1030 360 3 h 370 140 gel 350 4 h 330 160 - 360 5 h 290 460 _ 430 6 h 270 gel 570 7 h - 8 h

15-A

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ORIGINAL INSPECTED

I); le.fic- * ö example bonohreubbes the fact that G & mische aun epoxy resins ?! and copolymers other than the copolymers (I) according to The invention does not provide any improvements in thermoplastic properties of such other thermoplastic copolymers?}, even if these copolymers are more compatible Mix 7eifiO with the epoxy resins.

A mixture of 20 parts of epoxy resin B with 80 parts of a., Commercially available).! Block copoly (ester-amide) resins sold under the name Montac 1030. Montac is an IJare-nbcKoichnmig of Monsanto Company. The following bindings from urdon were obtained on substrates which were subsequently hit to approx. 235 ° C by v. ^r arerii

Tensile shear strength- T-Abziehfostig-j capacity, 813 in capacity aluminum '635 ρ

Montac 1030 93.5 1071

30 parts Montac 1030)

20 parts epoxy resin b \ 128.6 643

A certain increase in tensile strength is presumably due to a partial crosslinking of the copolymer by the epoxy resin.

8 ~ 0 9 8 * 5 0/0 769

Claims (1)

P ate η tan s ρ r ü ch β 1. Thermoplastic hot melt adhesive, thereby g o indicates that it is a mixture of an epoxy »! resin and a hydrocytinated poly (oster / ether) block copolymers of formula I: HO- (R ¹ O *; O ti COR "O - CO (R ¹ O) H P 0 η 0 _t COR ¹¹ OH —C- where R * and R "are alkyl groups, alicyclic groups, acyclic groups, aryl groups or arylalkyl groups having 2 to 12 carbon atoms, P is a number from 2.4 to 136.0, a is a number such that the portion of the" hard "segment in the first set of parentheses about 70 to 20 wt -. ■% of the copolymer, and b is a number such that the proportion of the" soft "segment in the second set of parentheses about 30 to 80 wt .-% of the copolymer. 2, hot melt adhesive according to claim 1, characterized in that the copolymer has a melting point of about 130 to 205 ⁰ C, an approximate molecular weight of about 4000 to about 25000 and that it is the reaction product of (1) a dicarboxylic acid or an ester thereof, ( 2) a low molecular weight diol; and (3) a di- functional polyether. 3. Hot melt adhesive according to claim 1, characterized in that the epoxy resin is melted at about 130 to 205 ⁰ C and is compatible with the copolymer when both components are melted. 809850/0789 ORIGINAL INSPECTED 4. Hot melt adhesive according to claim 1, characterized in that the proportion of Epoxyharzec 5 50 Gs \ '7. ~% of the mixture and that of the copolymer 50 to? 95, v. ¹ .- ^ of the mixture. 5. A hot melt adhesive according to claim 1, characterized in that the mixture has a tensile shear strength of more than about 63.2 kg / cm ~ on an overlapping bond; 2.5A cm 2.54 cm on a cold-rolled steel without a base coat that it has a peel strength of more than approx. 893 kg / m on aluminum panels with a thickness of about 635 jx m j oline base coat and that it has a pot life of as long as; 8 hours or more. 6. A method for producing a thermoplastic hot-melt adhesive, characterized that one is a hydroxy-terminated poly-cester / ether-block copolymer of formula (I): HO- (R'O -) - ■ - € - (ο COR "( σ —-C- - _4th O - _ —j ^ - - - - tf
O (D tt ' ,, COR "OH \ / tt * \ - / O b where R ^f and R ″ represent alkyl groups, alicyclic groups, acyclic groups, aryl groups or arylalkyl groups having 2 to 12 carbon atoms, P is a number from 2.4 to 136.0, a is a number such that the proportion of the "hard" segment in the first set of brackets is about 70 to 20 wt. -? 6 of the copolymer, and that the copolymer is blended with an epoxy resin to form a thermoplastic hot melt adhesive mixture. 7. The method according to claim 6, characterized in that the mixing step is the heating of the Copolymers and the epoxy resin to the molten state and the mixing of the molten copolymer with the epoxy resin includes to form a Sclimelzgomisch. 8. The method according to claim 7, characterized in that the mixture is heated ^{to about 130 to 205 ° C.} 9. The method according to claim 6, characterized in that in the step of forming the copolymer, a reaction mixture of (1) a dicarboxylic acid © or an ester thereof, (2) a diol with a low molecular weight and (3) a difunctional polyether under one pressure heated to cessation of the methanol distillation of about 1 to 15 mm Hg at a temperature of about 150 to 250 ° C and that the reaction mixture further 1 to 6 hours under a pressure of about 1 to 15 mm Hg to about 220 to 280 ⁰ C heated, .10. Process according to Claim 6, characterized in that in the mixing stage about 10 to 20 % by weight of epoxy resin is mixed with about 80 to 90% by weight of copolymers, both amounts expressed in% by weight being based on the total weight of the adhesive mixture . 11. The method according to claim 6, characterized. That the mixture is in a molten Condition holds to form a thermoplastic hot melt adhesive with a pot life of up to about 8 hours or more. 12. The method according to claim 6, characterized in that both the Copolymers and the epoxy resin are heated to the molten state and the molten copolymer and epoxy resin are formed a melt mixture mixed and that the melt mixture 809860/0769 applies to a substrate and the melt mixture on ümgebungs temperature cools to form a thermoplastic bond. 8098 60/0 768 _{0R1QINAL INS} p _E oted